No PWM signal for ESC 2 and 3

Hey,

I am trying to get my first quad flying but got stuck when calibrating the ESC's with the configurator.
When the ESC's are attached to the receiver they work all fine and obey the transmitter but when attached to the board only 2 rotate.
(I have the 1.9 version as shield with arduino UNO) When configurating the ESC's (Turnigy 18A plush), motors 1 and 4 where rotating in the + configuration but not 2 nor 3.
When I attached a scope to these two last pins, they stayed at 5V and where not being modulated as the ones of 1 and 4.
I tracked the signal to the pins:
front motor (motor 1) - D03
rear motor (motor 3) - D09
right motor (motor 2) - D10 left motor (motor 4) - D11
Can anyone help me with how I could get this PWM signals to work for motor 2 and 3?
thanks

It's fixed in 3.0.1, so if you're using 3.0.1, it's a hardware issue and not a software issue. There was some strange division of the motor commands for no apparent reason that was causing the PWM signals to be too short (<1000ms) to spin the motors.

Since you have a scope, test your Arduino to see if you're getting the PWM signal out of pins 9 and 10 with and without the shield attached.